An enzyme generally has high three-dimensional and chemical selectivity, thereby being useful in various reactions, and is used as a catalyst accelerating a reaction rate even under a mild reaction condition. However, since enzymes are generally costly, they have an economic problem in use in a large amount in an industrial scale. In addition, since most enzymes are insoluble in an organic solvent, they are limited in use in an organic chemical reaction. Therefore, in order to improve activity and stability of the enzyme and reuse the enzyme, research to immobilize the enzyme has much proceeded.
There are largely three ways to immobilize an enzyme on a polymer membrane. The first one is to adsorb an enzyme on a surface of a polymer membrane, the second one is to modify an enzyme to adhere it on a polymer membrane by a covalent bond, and the last one is an entrapping method to physically trap an enzyme in pores of a polymer membrane. Since it is the easiest and simplest way to adsorb an enzyme on a surface of a membrane by a non-covalent bond, much research thereon has been done. However, the enzyme may be easily separated, and the stability of the enzyme is relatively low. Modifying an enzyme and adhering it on a membrane by a covalent bond is the way to most stably immobilize an enzyme. However, since a process of modifying an enzyme is accompanied, the activity of an enzyme is lowered, and a process of immobilizing an enzyme is complicated.
The following patent document 1 relates to a method of immobilizing an enzyme using a double template, wherein the enzyme is immobilized on the double template to show a high catalytic activity. However, the preparation procedure of the catalyst is complicated, and the immobilized enzyme blocks pores, thereby making mass transfer difficult.